The present disclosure relates to a display apparatus of front-of-the-eye mounted type.
Display apparatuses of front-of-the-eye mounted type, such as head mounted displays which are used to be mounted on the head of a user using the display are developed. For one of user input methods for using a display apparatus of front-of-the-eye mounted type, voice input requiring no input interface such as a keyboard or a manual operation is useful. However, it is difficult to use a voice input method at public places where it is limited to utter voice or places where it is difficult to pick up sound due to the surrounding noise. In addition, for those users who don't want to utter voice, a voice input method is not recommended.
Therefore, a configuration in which a keyword to be entered by a user can be estimated from the voiceless movement of the user enhances user convenience. To realize this configuration, it is necessary to take an image of the movement of the mouth of a user with a camera or the like, but it is difficult to accurately take an image of the portions around the mouth if the head of the user makes a movement or the user himself or herself makes a movement.